Collaboration Agreement - Schedule of Collaboration Revenue (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2014	Mar. 31, 2013
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Attributable to U.S. XTANDI sales	$ 62,225	$ 37,689
Attributable to ex-U.S. XTANDI sales	5,731	0
Attributable to up-front and milestone payments	19,233	8,465
Collaboration revenue	$ 87,189	$ 46,154

Revenue earned from the amortization of non refundable upfront cash payment received under collaboration agreements over the expected performance period and milestone payments earned.

No definition available.

Name:	mdvn_CollaborationRevenueAttributableToUpFrontAndMilestonePayments
Namespace Prefix:	mdvn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration